Method of manufacturing lock nuts



11 sheets-smelt 1 Marchv 15, 1949. J. H. S'T'OVER, m

METHOD OF MANUFACTURING LOCK NUTS Filed Oct. 9,1945

ATTORNEYS March 15, 1949.

J. H; sTovER, 111: METHOD OF MANUFACTURING LOKCK NUTS Filed Oct. 9,l 1945 @.1 Sheets-Sheet 2 ooooooooom! Nmw mw.

h l l l' E ATTO R N EY March l5, 1949*. 1 J. H. sToVER,J1I 2,464,728

METHOD OF MANUFACTURING LOCK NUTS Filed oct. 9, 1945 l v 11 sheets-sheets ATTO RN EYS ico March 15, 1949. J, H, STOVER, m 2,464,728

METHOD OF MANUFACTURING LOCK NUTS Filed Oct. 9, 1945 11 Sheets-Sheet 4 Wye?.

lNvEN-roR JORDAW h'. Jo'vERzZZ ATTORNEYS Mah 15, 1949. .1. H. STOVER, 111 2,464,728

METHOD oF MANUFACTURING'LOCK NUTS Fled'OGt. 9, 1945 11 Sheets-Sheet 5 f4.7 26; M7' i i .326 g5 y J5 i 37 446 r .725 .446'

l March 15, 1949; H, STOVER,`m- 2,464,728`

- METHOD OF MANUFCTURING LOCK NUTS Filed oct. vsa, 1945 y11 sheets-'sheet s l INVENTOR JORDAN H. JToz/ERZZZ' V ATTORNEY5 March 15, 1949. J, H, STOVER, 11]; 2,464,728

METHOD OF MANUFACTURING LOCK NUTS Filed oct. 9, 1945 1.1 sheets-sheet 7 -Joem N v H. :fors/azz?- .59 BY E E G l l h f 'ATTORNEYS March l5, 1949. J. H. sTovER, IIL 2,464,728

' METHOD OF MANUFACTURING LOCK NUTS I Filed oct. 9, 1945 11 sheets-sheet s lNvEN-ron C20/@JAN H. Jol/ERZZZ ATTORNEYS March 15, 1949.

J. H. STOVER, 111

METHOD `0F MANUFACTURING LocK NUTS Filed Oct. 9, 1945 11 Sheets-Sheet X9 III\ NNY) INVETOR JORDAN JTOl/ERHZ b am @ma l ATTORNEYS MarCh 15, 1949. J, H, STOVER, 111 2,464,728

METHOD OF MANUFACTURING LOCK NUT Filed Oct. 9, 1945 11 Sheets-Sheet 10- INVENTOR JORDAN JTOVF/Z LU ATTORN EYS March l5, 1949. J. H. STOVER, 111

METHOD OF MANUFACTURING LOCK NUTS 11 she'ets-sreet 11 Filed Oct. 9, 1945 mmf . INVENTOR Joao/w f/ from: za

ATTORNEYS l n Y r B fffiifurb. u i \|-Ii wml r wN/, L N f nu. U-\I\MN. n u m Q G/ n ina'terial.l ,-1 `ting specially shaped and inely madeothreads ori-both nut andbolt, and the provision oispecial. lock sections ,formed `integrally with or. attached:` to the-shut., .Proposalsalsdhave heenmariestuY Patented Mar. 15, 1949 Jeroen n. stoven; In, Easton, Ps.; assigns to Stover Lock; Nuti Vlla Machinery: Corporation, .a

corporation oi Delaware Original' application October Slg-11945,' Serial No. .$21,266. Divided and this-application- October 9, i945, Serial N0.-621,265 v 14 Claims.. (CL. 10h-86) This invention relates to loclsnuts, and'h-asforA its objectrcertain improvements inthe method of;

making lock nuts.

Nuts ordinarily are madewith a pitch diam'- eter suicientlygreater than the pitch diameter of amatingbolt so .thatthe nut may be screwed freely onto the bolt. This so-called t tolerancemay -vary considerably, depending upon the size of' the mit and the iineness of fit desired;l In anyv event, however, it is suicient so that until tl'ieA upper or the lower side of the bolt th.reads,g ahda in consequence there is only slight frictionr and resistance `to turning. When the nut becomes tightened against the,r work, the` upper sidesr of the threads on ther nut Contact the lowersides; of the threads on the bolt with a pressurer dretcrl ined by thel force-Witli;\vhich the nuliiS' tightened, and the friction resulting.;from-the pressure between the interengaging sides ofthe 'threads serves to holdthe nut-mits tightened position.

The objection to this kind of nut is that it is, easilyloosened, becausey whenever the pressure between the'flcwer endiof the nut andthework is; relieved as Vresult of "vibrations wea-r, ,orother cause, the pressure betweenthe inter'-engagingV sidesof the threads is also1 relieved so that there is no longer sufficient friction to prevent the nut from being. slowly backed off the boltby vibrael tion, shock, orv the like.

Many dierent expedients have been proposed.,v and some 4have come into general use, to prevent acciaio-tcl loosening of tightened nuts. The; Well-'known split lock-Washer, the use of a sep,- arate locksnutand the use of Cotter pins througll cotter ways formed in the nut and through a hole; in the holt, arevprobably the` most familiar of these expedients. Anothery proposalis to, insert elastic. material in a; groove specially provided around the threaded hole of a nut to provide a locking. eiiect. The eective use of such anut is limited to the life of the elasticmaterial While continued in use with the'work to Which ittis rst applied or thev nut is greatly limited in the number of times it can be re-used because oi damage to andY loss of elasticity of thevelaelic Other expedients have. vinvolved out,

deform the nut as a Whole, or to provide specially formed' .sectionsoff. the nut which may biedeormed to;v lock with the; bolt. Such; sections oitenzareoslottedf ihzvarious ways. with' the idea ofenhaneing the looking-,action of vthe;defollnedf sect-ion, Thesevariousyiprior:expedientsareasilbs. jectato .the disadvantage thatfasepaiate locking piece-is: required, or tothe disadvantagezoffb ing-y ineffective or `only moderately.; effective.; diiiieul-t'; and; expensive to manufacture! accu: lrately ahdiinfquantity.- For eaample,1proposalsf to. distort the nut over, its entirelength 'havebeenunsuccessful-,because nuts sol distorted to.4 an; ci: fectivefdegree canhotbeastartedon theboltf exev cept g with greatdificulty. Proposals; l to deform', specially provided-sections ofithefboltlhave been; unsuc'cessiul becausel the: deformedl sectiiona; which ycommonly are slcttedinggsoine manner, doy notprovide a. satisfactoryflock andl are expensveto manu-facture.-

Another lock nutproposed is. one with opporsitey *sides` oi a@ blank. nut.' forced toward, one ane other to pro-vide oval or elliptical opening at. the Eton `while:r maintainingthe ,lower part. of, the: holeof the nutcylindrical or.circular. Although Suchev lock. nutswas.. proposed,many years agoin 'British Patent.;- 1,003, of 1.88.0).` so'v far. asfs known. it., has.A had. no. commercial success.A lf theslock., nut deformed',- too. little,A it. is. Worth: less. s. .I f. itoissdeformedtoo .much it Aisahot satie. isfactory. because useof. the locks uut dal'rieures.v the threads of .the nutas. Well as ofv thebolt or, mating, screw, and` thedesirednon-.slppig gripping action is not.,ohtreiined.l If theinsui-'j cientlyV deformedlock nut'is given additional die:

, formatonlthere is; however no, Way` off telling' Whether the deformationistoo. milch .0r toolittle; except .b5/factual use. Actual use is outof the ,question when ,the lock. iuftssare` madey by the thousandsl and..shipp1ed to remote parts .for `ulfifaililis use...

Investigation confirms my discovery thatlockl. nuts .of the propert'ype and amount ofdef'ormation may be;-v consistently reproduced or` duplicatedandthat the deformation is sufficient to` assureq adequate gripping orlockingV-` action between the lock nuts and-- theirk matingbolts or screws.- l A f The lock nut preferably comprisesfa-nuirbl'anlsI liav-irig.,athreaded ope-ning, opposite sidesmifthe main. body: ofi-thelol-ank` being compressed at the=topsportionsthereoff'tova: depth` 01?; .1;21 tof the nominal diameter. o-thelmating. screw.; be. youd theelastic of :the blanklto provide a permanent `distortionin the blank and to causeV tile-:tooor.v the:` opening: tosassume.: a .geneigally ellipticahshape with. thassidesioniesopenng mi the minor axis pushed toward one another and with the sides of the opening on the major axis pushed away from one another while the bottom of the opening remains substantially circular with a diameter greater than the minor axis and less than the major axis. The width of the top of the opening along the minor axis is reduced by the distortion by an amount equal to the fit tolerance plus 0.001 to 0.010 inch.

In a presently preferred practice, the width of the top of the opening along the minor axis is reduced by the distortion by an amount to produce a friction locking torque of 115 D2-4 to 820 D2-5 on a mating screw within the dimension tolerances of its class of t; in which D equals the nominal diameter of the mating screw and the result obtained is pound inches of torque.

In accordance with the method `of the invention, a mandrel with a stop portion of predeterf mined size is inserted in the threaded opening of a blank nut. The upper portions of opposite sides of the nut are then forced toward one another until threads in the opening of the nut engage the stop portion of the mandrel to distort the upper portion of the nut a predetermined amount.

The depth of squeeze of the upper portion of the main body of the blank is highly important. A decrease in the depth of squeeze results in less sensitivity (variation of friction torque in relation to change in bolt diameter) to bolt diameter and less life (re-use factor). An increase in the depth of squeeze results in greater sensitivity to bolt diameter and greater life. The object is to select a depth of squeeze adapted to yield the least -sensitivity with the greatest life. depth of squeeze is less than 1/4 of the bolt diameter, the life of the lock nut is less than its `Draciti-cal limit. Ii the depth of squeeze is more than 1/2 of the bolt diameter, the sensitivity of the look nut is beyond the practical limit. For these reasons, opposite sides of the main body of the blank are compressed only at the top portion thereof to a depth of 1/4 to 1/a, preferably about the nominal diameter of the mating screw or bolt. This is particularly `true of nuts ranging, for example, from #8 machine screw to 1 in size.

Lock nuts of the character described may be readily applied [to a bolt or mating screw. They may be screwed lon part way by hand since the lower part of the nut is substantially undistorted. At .this point, `the inwardly slanting opposite sides of the threaded opening in the nut come into conltact with the bolt threads and as the nut is screwed on further, the bolt .threads force the [compressed sides of the nut apart against the spring action of the distorted nut.

These and other advantages of the invention will be b etter understood by referring to the accompanying drawing, taken in conjunction with the following description, in which- Fig. 1 is a side elevation of an apparatus illustrative of a practice of the invention, for the most part showing its inner mechanism and not its outer casing or covering; y.

Fig. 2 is a partial plan view of the loading end of the mechanism;

Fig. 3 is a vertical sectional view of the apparatus, taken approximately along the line of travel lof the mandrels, showing the endless conveyor and part of the driving mechanism;

Fig. 4 is a partial plan view of the endless conveyor;

Fig. 5 is an exploded view of a unit of the endless convey-or showing a sprocket chain link, a

If the f.

4 mandrel support land a mandrel with a nut mounted thereon;

Fig. 6 is a fragmentary side view of a. small section of the endless conveyor;

Fig. 7 is a sectional plan view .on the line 1-1 yoi Fig. 1, showing the endless conveyor, the squeeze rolls, the driving mechanism for the endless conveyor, the adjusting mechanism for moving the endless conveyor laterally and a portion of the driving mechanism for the knurling de- Vice;

Fig. 8 is a sectional view on the line 8 8 of Fig. l, showing the mounting of the squeeze rolls, the mechanism for driving the same and a portion of the adjusting mechanism for moving one of the squeeze rolls laterally;

Fig. 9 is a fragmentary sectional view on the line 9 9 of Fig. 8, showing the adjusting mechanism for moving the endless :conveyor and its associated parts laterally, the squeeze rolls in phantom and part of the adjusting mechanism for moving one of the squeeze rolls laterally;

Fig. 10 is an enlarged sectional v-iew of the mandrel support, showing .a generally cylindrical mandrel and a nut mounted thereon, before it is deformed, similar to the assembly shown in Fig. 5;

Fig. ll is a similar sectional view showing the nut after it has been deformed by the squeeze rolls;

Fig. 12 is a view similar to Fig. l1 but showing a generally tapered mandrel;

Fig. 13 is a plan view of -a lock-nut illustrative of the invention;

Fig. 14 is a side elevation;

Fig. 15 is a perspective view partly in section;

Fig. 16 is a side elevation `partly in section, showing the lock-nu-t and a bolt in applied form;

Fig. 17 is a view sim-ilar .to Fig. 9, but showing the relative relation of the parts when deforming a smaller nut;

Fig. 18 is a section yon the line |8--l8 of Fig. 17, showing the aligning mechanism for presenting a pair of opposite sides of the nut to the squeeze rolls; i

Fig. 19 is an exploded view showing the pedestals, [the fixed bearing blocks and the movable bearing blocks for the drive shafts of the squeeze rolls and the appurtenant parts in the adjustment mechanism for moving 1one of the rolls laterally;

Fig. 20 is a general plan view of the endless conveyor support and its rel-ated parts, the endless conveyor itself being Iomitted except for Fits Chain sprockets;

Fig. 21 is a side View, similar to Fig. 1, -of the endless conveyor support and its related parts, the endless convey-or itself being omitted except for its chain sprockets, which are shown in phantom;

Fig. 22 is an enlarged elevational view of the knurling device shown in Figs. 1 and 3;

Fig. 23 is an end view of the same knurling device;

Fig. 24 is a section on the line 24-24 of Fig. 22;

Fig. 25 is a plan view confined to the tension control mechanism of the knurling device;

Fig. 26 is a sectional view on the line 26--26 of' Fig. 23;

Fig. 27 is an enlarged elevational view of the adjusting mechanism for moving one 0f the squeeze rolls laterally, as shown in Figs. 1, 7, 8, 9, 17 and 19, and showing more particularly the connecting mechanism with an indicator for showing the amount of lateral movement of the squeeze roll; and

.affront viewpf the indicator and its` associated-mechanismi i Referring rst to Fig. 1, the nut deiorming and; Kunming-'apparatus comprises a `pair yofupright spaced'fpedestals 3.0 :and 3| maintained in spaced relationship 'at-theirbottom yeloyzmeans 'of a pluralityof rchannels 32, 33. Thetpedestals in turn support aloading `table 314, acasing or cover r35, moet of which fis `shown broken away, an endless conveyorfa :pair `oispaced and opposed squeeze rolls .B' and 38,.;3 knurl-ing device 39, andthe nec- -essaryidriving mechanism 40 for operating the apparatus. VThe driving lmechanism comprises a motor l vwitha chain sprocket 46 mounted on a shaft M. imfendless sprocket chain 48 is mountedgonzthesprocket and a larger sprocket 49 mount-A edton adr-ive -shaft '50. The drive .shaft is employedf-zito drive the tendlessiconveyor as wel-l as .thecsqueez-e rolls.

'Referringrsnext tto Figs. .8 land 19, sprocket 49 andrdrivefshaft' are supported in -Xed bearings 51Y rand 52-suitably mounted .on brackets 53 and 5I secured'rto pedestals :130 `and 3|, respectively. A bevelpinion 55'is suitably secured to an intermediate portion of drive shaft 50, the bevel pinion meshing with a bevel .gear 56 integrally mounted on the yflower end of aavertica'l shaft 51. The shaft extends y'upwardly through a collar 58, a lower xedbearing block 59 provided with a lower bearing hub 60, and an upper bearing hub 6|, squeeze roll 39,:upper xedtbearing fblock .62 provided with ailowerfbearing hub 63 4and van upper bearing huh S614; and va spur gear I6.5 integrally secured to theupper end. .Ancud `,plate v66 is bolted to the endstofl'lower fixed bearing .block 59 .and upper fixed'bearing block 6:2. Spur .gear 65 meshes with' aacompan'ion spur gear '1.0y integrally secured to the .upper end of avertical shaft 1|. This shaft extends .successively :through an anti-friction washer '12, an .upper `laterally sliding bearing block '.13, provdedwth four (4) guide `bars 1.3', as..shown, extending through a complementary' slot :114 'in :lupper yfixed bea-ring block 62,' squeeze roll 31 a lower laterally-sliding bearing block 15, provided with guide bars v'15', as shown, extending througha .complementary slot in lower fixed bearing '.block 59.

"The 4arrangement shown lpermits -avariable spacef80 betweenzsqueeze rolls 31 and 38. The appairatus is vso designed that the space may be variedftofaccommodate nuts of various sizes. To thisen'd, l:upperll--xed'beari-ng block 62 is provided at itscnd with a lateral opening 8| accommodatingsa .draw-'nut 62. 'The draw nut, as shown in El'glil, is provided with a vgenerally rectangular endorf-baseportion 83 and -a cylindrical hub portionr .adapted to vfit snugly in slot .14 and lateral opening 9|, respectively. In similar fashion, lower fixed .bearing block 59 iis yprovided at its end With'a'latera'l .opening 85 accommodating a draw nut'. The "latter .draw nut, as also shown in Fi ,'19, is provided with'a generally rectangular andi-enbase portion''l and a cylindrical hub portion-:88 .adapted to vlit snugly in slot '16 and lateral opening "85 respectively. An end plate 89 is secured v#to .the free ends vvoflower 'xed bearing 59 and :upper fixed 'bearing block 62, as shown in Fig.` .8, by a plurality of bolts. 'Cylindrical `hub portion f8.4 .of draw vnut '82 iis Iin turn provided with alateral square-'threaded opening 90 into which ftsa .complementary square-threaded draw lscrew 91|, .the other end o'f which terminates in a shaft extension 92 extending'through the bearing 93 oa'draw bar v.94;setured to upper -lateral sliding 'bcaringblcck '13 :by means .of :a plurality .of bolts.

ole. b21! In similar fashion, 'hub portion 8 of .draw nut' is :provided with lalateralsquareethreaded opone. ing 95 Vinto .which .frits 'n..complementary 'squarcthreaded draw screw 96, the .other lend A.of which.

terminates .in va shaft extension 91 .extending through .the bearing 98 l.of .a draw bar .99 secured to lower lateral slidingfbearing block '.15=.by meansof .a plurality of bolts.

As @show-n .in Figs. Band 19, end plate 89zisi'provided at :its end with;s10ts |:0.0 andv 40| kto accom modate ...draw .-screws';9l .and 196,;respectively. A- squeeze .rolladjustmentggear |015 :is integrally ,ses cured to the freeend of .-shafticxtension 92,1the hub `portion of the .gea/r being .in contact with' hub 93 of `draw bar-.94 `.to make ta tight assembly.

A ,complementary/squeeze Iroll adjustment gear..

|96 is integrally secured tof-the ireecnd .of the shaft .extension :911, 'the hub lportion of :thefgear being in .contact with hub :9.8 of @draw bar .'99 :to-

make a tight assembly. A squeeze roll adinet ment pinionY |01' fits Arnes'hed .engagement with' and between .adjustment .gears |95 and ipfthe pinion bei-ng `integrally .secured to axshait 1.0.8,'y

the inner .end lof rwhichzts .a Isleeve bearing .1:59

fitted in and secured to the mid-portion .of `fend 1plate;89. A pair .of @spaced flanges M0 and .|l|| provide aspace in Iwhich gears |05 and 106 :may turn in meshed .engagement with .the '.teethaof pinion |01. The .other end of shaft -gl 08 ris squared into a gripping `.portion 1| l2 ladaptedto l'itinto f-a.

H9 and |20 attached toa :generally .horizontal support |2| by .a plurality .of bolts .(see Fig. 7). The endless conveyor .proper comprises .a pair .of spaced endless Asprocket .chains |25 and |215 mounted .on a pair `or" sprockets |21 and .|28 are. spectively, integrally .secured to vshaft H8, .and :a pair of spaced sprockets |29 'and' |30 mounted? on a shaft 13|, the ends of which zare .supported in Va pair of spaced bearings |32 vand/1.33 .secured to horizontal support |2| with a -plurality of. l bolts (see Figs. and 21).

A plurality o i |35 extend completely'around the endless con.- veyor, the links A:being attachednat their sides to sprocket .chains .and |326. A .sheet metal guard 36 is riveted :to each 'link to provide :a cover over the space betweeniadjacent links (see Figs. 3, 4, '5 a-nd `6). Each 'link '.is, in addition, provided with a 'centra-l .opening |311 -.('see Fig. 5;) extending through a depending boss |38 vunder each link. A mandrel .support `|39 nts in open ing |31, the upper .end .of which is provided with' an enlarged boss Cportion |40 'having `a vertical opening |41 anda "lateral set screw |42. v'The lower part .of the mandrel .support .ls prt'ividedwith a removable and adjustable collar |43 rse;- curable to the ,support by means of a .setscrew |44. The construction is .so designed that thel bottom of boss y:|40 .rests against t'lie'ftop of flink while collar l|43 .bears upwardly against thebottom of boss il'38in orderto'assure a l'tight assembly. Opening 1 41 1in boss h.Ulli is designed' to receive a depending extension arm '|45 of aman.- drel 46 adapted'to t into -the'threaded'hole .of a `blank nut 141, a `'laterally extending base T4118' being provided between V.the [mandrel @proper and the .depending extension `arm which is designed' to bear against the top of boss |40. This mandrel is also shown in Figs. 10 and 1i. Set screw |42 may be turned to secure the depending extension arm securely.

As shown more particularly in Figs. 20 and 21, longitudinal support |2| is in effect divided into a front portion |50 and a back portion |5| which are joined by a constricted central portion |52 reinforced by a pair of spaced reinforcing members |53 and |54. .Front portion |50 has a cutaway portion |55 to accommodate sprockets |29 and |30, and back portion |5| has a cut-away portion |56 to accommodate sprockets |21 and |28. Front portion |50 is provided with a' pair of slack-takeup devices and |1| adapted to move bearing blocks |32 and |33, respectively, in order to take up slack in endless conveyor 36. A pair of spaced mandrel guides |12 and |13 extend lengthwise across the mid-section of longitudinal support |2|. Guide |12 is fastened to brackets |14 and |15, while guide |13 is fastened to brackets |16 and |11. A pair of sprocket chain guards |18 and |19 similarly extend across longitudinal support |2| and are secured to the same brackets.

As shown in Fig. 8, constricted central portion |52 of longitudinal support |21, in other words the section of the support between front portion |50 and back portion |5I, rests in a recess |80 in lower xed bearing block 59, the recess being somewhat wider than the constricted central portion to permit lateral sliding movement of the latter. An aligning plate |81 extends across the top of constricted portion |52 as well as front and back portions |50 and |5| directly below mandrel guides |12 and |13. As more particularly shown in Fig. 8, each mandrel support |39 is adapted to move along the top of the aligning plate, thus accurately locating each nut |41 mounted on its mandrel with respect to squeeze rolls 31 and 38. To assist in saddling longitudinal support |2| on lower fixed bearing block 59, front portion |50 of the longitudinal support is provided with a pair of vertically-spaced and laterally-extending pads |82 and |83 adapted to bear against the side of the bearing block. A similar pair of pads |85 and |85 is provided on back portion |5| of the longitudinal support adapted to bear against the other side of the bearing block. A pair of spaced struts |06 and |81 extend from front part |50 to back part |5| of longitudinal support |2| directly below bearing block 59, the struts being provided with a pair of nuts at each threaded end to permit the desired adjustments.

Referring more particularly to Figs. 3, 9, 17 and 18, the apparatus shown includes a nut-aligner |90 which comprises a pair of spaced and parallel guide wires |9| and |92 extending in the direction of the endless conveyor, wire |92 extending forward farther than wire |9|. The wires are spaced a predetermined distan-ce apart so that when nut |41 mounted on mandrel |45 is passed toward the squeeze rolls and the side of the nut strikes Wire |92 and passes between both wires, the wires function to align opposite sides of the nut in parallel relationship with the wires so that the opposite sides of the nut are presented simultaneously for engagement with the squeeze rolls. The ends of wire |9| are secured to a pair of upright supports |93 and |94, in turn secured to brackets |95 and |95, which are fastened to the sides of upper xed bearing block 62. The ends of wire |92 are similarly secured to a pair of upright supports |91 and |98, in turn secured to a lateral bracket |99 which isfastened to the inner end of upper laterally slidable bearing'block 13.

A'draw nut 205 with a generally rectangular end or base portion 205 andra cylindrical hub portion 201 is secured to front portion |50 of longitudinal support l2| (see Figs.'3, 7, 9, 17, 20 and 21, and particularly Fig. 17). In similar fashion, a draw nut 210 with a generally rectangular end or base portion 2li and a cyl-indrical hub portion 2|2 is secured to back portion |50 of'longitudinal support |2|. 201,.and 2|2 are provided with square threaded lateral openings into which fit complementary square threaded drawscrews 213 and 2|4, respectively. Draw screw 2|3 is mounted in abearing .'2I5 integrally supported by a bracket 216 secured to lower xed bearing block 59, the draw screw being provided with a pair of collars 2|1 and 2|8 secured thereto at either side of bearing 2|5.'l An -endless conlveyor adjusting gear-219 is mounted at the other end of the draw screw. 'In similar fashion, draw screw 214 is mounted in abearing 225 integrally supported by a bracket 226 secured to lower xed bearing block 59, the

draw screw being provided with a pair of col-y lars 221 and 228 secured thereto at either side of bearing 225. An endless conveyor adjusting gear` parts, back and forth, indicator shaft 231 also' The outer end of indicator shaft-231 extends through a fixed Ibearing in ycasing or cover.

turns.

35. An indicator pinion 238 .is secured to the indicator shaft intermediate hub 235 and cover 35, the teeth of which mesh with the teeth o-f an indicator gear 230 mounted on a second indicator shaft 240 extending through a bearing se- -cured in cover 35, the outer end of shaft 240 .being provided with an indicator hand 24|. In similar fashion, the outer end of first indicator shaft 231 is provided with an indicator hand 242. Referring next to Fig. 28, it will be seen that indicator hand 242 is associated with an outer calibrated scale 243, advantageously subdivided'into 'thousandths of an inch. As shown, the scale is` subdivided into main graduations of ten thou- Sandths of an inch, totalling 250 thousandths; in other words, ly-inch. Indicator hand 24| is associated with an inner calibrated counter scale 244 subdivided as shown into main graduations of 25 units, totalling |50. indicator hand 242 in a clockwise direction from zero all the way around the scale back to zero simultaneously moves smaller indicator hand 24| in a counterclockwise direction one main graduation, namely 25 units; that is, 1/4 inch. A movement of the smaller indicator hand from 0 to 0, namely 150 units, corresponds to 11/2 inches. The object of the arrangement described is to indicate to the operator the amount of space ex-A isting between squeeze rolls 31 and 38 or the amount of adjustment to be made inthe space between the rolls. The size of pinion |01, gears |05, |06, 2|9 and229 and their teeth and the:

Hub portionsY Movement of larger' sizeof draw screwsI 91, 96, 213 and 214 and their threads are so proportioned and correlated that wherr crank |13. is turned, squeeze roll 31 moves 'laterally' twice as far as endless conveyor 3B. This permits the centering of each nut 141 midway in `space 80 between squeeze rolls 31 and 38.

As stat-edV above in referring to Fig. 1, the apparatus includes a knurling device 39. The object o'f the knurling device is to provide the deformed nuts, that is the lock nuts, with a suitalbl'e marking so that they may be distinguished readily from conventional nuts and to indicate What portion of the nut is deformed. In the present-construction, the knurling device cuts a criss-cross'p-atte'rn of lines in the top of the lock Th-e 'dev-ice is shown in more detail in Fig. 3, and particularly Figs. 22 to 26, inclusive. Power take-off shaft 118, which operates endless conveyor 35, is also used to operate the knurling device. For this purpose, the far end of' the shaft is provided with a gear 251i which in turn-meshes withy a gear 251 mounted on a horizontal jack shaft 252 extending back o-ver and across the endless conveyor. The jack shaft is supported ina pair. of spaced bearings 253 and 2.54,. the former' bearing being bolted to a pair ofi spaced vertical columns 255 and 2515 and the latter bearing. being bolted to a similar pair of spaced; vertical columns 251 andv 255, the bases of the? columnsbeing bolted to back portion ofhorizontal support 121. The other end of the jack shaft isfittedl with a sprocket 259 on which is mounted an endless sprocket chain 2511. also mounted ona sprocket 261 on a shaft 252 extending laterally back over the endless conveyor. Shaftff262 Arests in twosplit bearings 2113 and 254,

-witha knurler,Y roll: 2155 positioned therebetween,

the lbearings extending horizontally between a pair of vertical columns 266 and 251 near one endl and asimilar pair of vertical columns 253 and 269- nearl the other end, all of the columns being secured atl their bottoms to back portion |51 of horizontal support 121 and their upper ends being threaded, as shown.

The four upright columns are fitted with three piatens, alower platen 210, a middle platen 21| and an upper platen 212. The upper platen is providedl withv a rising central rib section 213 at one end and a similar rising rib section 214 at tlie'othery end, these ribbed sections connecting withV a centrally disposed and. a wider bearing portion 215. The threaded end of each vertical column 261, 265 and 259 fits in a threaded sleeve 2116 extending, through the platen, the sleeve in turnbeing keyed in each case to a sprocket 211, theiconstructiori being identical for the assembly ati they upperl'end1 of the three vertical columns. Thefourtn vertical column 256 is provided with a modiedSp-rocket 218, secured to a special sleeve 219, the upper end of which terminates in an extension portion1281l adapted to fit into a socket crank; Anendless sprocket chain 281 is mounted ori-.the fourrsprocketsl -Asvertical shaft 285 extends through bearing portioni- 2150i upper platen 212, the lower end terminating. in'. a; head 286 to help hold it in position, the upper portion of the shaft having keyed thereon a pinionv 28.1' meshing laterally with a pain-of gears 2/88fand 289. The upper end of shaft 285 terminates in an extension portion 291i adapt.- edtofit a' socket crank. Gear 288- is integrally secured to the.y upper end of a thrust screw 291v extending-through. av threaded hole in bearing portion; 211.5, the.4 rlowerpend .ofA the thrust screw: beingvffa'daptedztoengage -a central rib 292- of middle platen 211. rl1-he gear 259 carries thrust screw 293 which also engages ri'b 292. An upper boss 291 and a lower boss 298 are provided at each of the holes in lower platen 211) through which the vertical columns extend, to provide more bearing and guiding surface. Split bearings 2553 and 25:1 are integrally securedl to the bottom of lower platen 211i by means of a plurality of stud bolts 295. The lower platen has a cut-away portion 31111 through which the upper portion of knurled. roll 2155 extends. Reinforcing plates 3131 are secured at opposite sides to strengthen the platen in the areas adjacent cutaway portion 300.

A plurality of appropriately spaced bolts 305 extend through upper platen 212, middle platen 211 and lower platen 2111 and split bearings 263 and 2511 to .help support the lower portions of the split bearings. In addition, each bolt is provided with a compression spring 3115 between middle platen 211 and lower platen 2111-. As a result of the arrangement described, shaft: 262 and therefore knurling roll '265 are held in a position to be moved upwardly or downwardly, as desired.

A rough approximation for the operative position of the knurling roll is ladvantageously first obtained by fitting a socket crank ony extension portion 2811 and turning it to move sprocket chain 281 around sprocketsA 211 and 218 and hence to move upper platen 212 up or down, as required. This is done to place thrust screws 291 and. 293 in a favorable operative position. When, therefore, a socket crank is tted onto extension, portion 2911 of vertical shaft 285, thrust screws 29| and 2113` are moved upwardly or downwardly, depending upon the direction of rotation of the socket crank. If thrust screws 291 and 293 are forced downwardly against central rib-292 of middle platen 211, springs 306 are placed under greater compression, thus forcing lower platen '21B and hence shaft 252 and knurler roll 265 downwardly. In other words, the knurler roll is forced more heavily against the top of deformed nu-t 141, and succeeding deformed nuts 141. If, however, the pressure of the knurler roll on the nut is too much, the operation may be reversed to release the compressive force of springs 395. Minute control of the amount of pressure of the knurling roll on the nut may thus be obtained by the use of the socket crank on extension portion 290.

, The apparatus shown includes special means for withdrawing the deformed nuts from the mandrels as the endless conveyor moves around to its discharge end (see Figs. 1, '1 and 22), For this purpose, the apparatus includes a pair of spaced supports 311i and 311, the upper ends of which are attached to upright columns 251 and 255, and the lower ends to back portion 151-v of horizontal support 121, A pair of spaced deformednut strippers 312 and 313 are suitably suspended from supports 3111 and 3151Y by a plurality of lateral arms 314. These strippers consist of strips of thin curved sheet metal, the linner edge portions of which are adapted to engage the bottoms of the deformed nuts. As shown in Fig. 1, the curvature of the strippersv is such as to follow each mandrel to its upper end as it moves around the discharge end of the endless conveyor; that is, around chain sprockets 121 and 128. Therefore, as the fore or top parts of the strippers engage the bottom of each nut in its normal position on the mandrel, and the mandrel continues in its 'course around the a threaded central opening 33|.

the bottom portion 332 of the blank is circular Asprockets, the deformed nuts ride on the strippers land are gradually moved upwardly to the top or end of the mandrels, from which the nuts are dropped. A chute 3|5 is located at the discharge end of the endless conveyor, being secured to cover 35, as shown in Fig. 1y to catch the nuts and direct them into a bin 3I6 located under the chute.

In referring to Figs. 5, and l1 above, brief reference is made to mandrel |46. As more clearly shown in Figs. 10 and 11, the mandrel proper is divided into a lower cylindrical base portion 325, adapted to fit loosely in the lower portion of blank nut |41, and an upper cylindrical stop portion 326 of predetermined size adapted to act as a stop (see Fig. l1) when squeeze rolls 31 and 38 force opposite sides of the upper portion of the nut toward one another and the upper threads of the nut are brought into engagement with the stop portion. A modied form of mandrel |46' is illustrated in Fig. 12, in which base portion 325 and stop portion 326' are in the shape of a frus tum of a cone. In both constructions, the surfaces are relatively smooth. The presently preferred construction is that of Figs, 10 and l1 z because the cylindrical base and stop portions may be readily machined to size.

Lock nut |41 is shown in hexagonal form with The opening at but at the upper portion 333 it is generally elliptical, having a minor axis 334 and a major axis 335. The elliptical shape of the opening at the upper portion of the blank is the result of compressing or squeezing the upper portions 336 and 331 of opposite sides of the main body of the blank toward one another at the top portion to la depth of 1A. to 1/2 the nominal diameter of the mating screw beyond the elastic limit of the -blank to provide a permanent distortion in the blank with the sides 338 and 339 of the opening on minor axis 334 pushed toward one another and with the sides 340 and 34| of major axis 335 pushed away from one another. The width of the top of the opening along the minor axis is amount to produce a friction locking torque of 115 D2-4 to 820 D25 on a mating screw within the dimensional tolerances of its class of fit, in which D equals the nominal diameter of the mating screw and the result obtained is pound inches of torque. This value may be readily determined vby screwing the lock-nut on a mating screw, such as a bolt, with a conventional torque wrench.

Fig. 16 illustrates the use of the lock-nut when screwed tightly onto a bolt 342 to secure the pieces of work 343 and 344. When the nut is applied to the bolt, it may be screwed at least 1A; of the way freely by hand since the lower part of the nut is not distorted. As the nut is screwed further onto the bolt, the distorted upper portion of the nut tends to assume its original undistorted form due to the resiliency of the metal Wall of the nut. The bolt `threads force the compressed sides of the nut apart against the spring action of the distorted upper portion of the nut.

As indicated in the drawingthe threads along the inwardly distorted sides 333'and 333 on minor axis 334 of the nut tightly engage their mating threads on the bolt. This spring action causes the nut to grip opposite sides of the bolt and by reason oi the amount of the distortion to make a strong friction pressure contact on the top as well as on the bottom of the bolt threads.v Accordingly, the nut not only grips the bolt tightly but creates an additional friction area on the threads by pressing against the upper as well as the lower sides of the bolt threads even when the nut is tightened against the work.

In order that lock nuts made according to the invention be of general utility, it is highly desirable that they be adapted to receive standard socket wrenches and box end wrenches, as well as open end wrenches. In distorting the nut, its outside dimension measured at right angles to the direction in which it is squeezed is increased slightly. In other words, the distance across the nut is decreased along minor axis i4 and increased along major axis i5. rlhis increased outside dimension along the major axis may be too great to permit placing a standard socket wrench or box end wrench -of nominal size over the nut. It is therefore desirable to make the nut blanks in, for example, hexagonal form, somewhat smaller in cross-section than the conventional practice so that when the distance across the top yof the lock nut is increased along its major axis, the nut may nevertheless lit into the wrench.

Some important advantages oi the lock nut of the invention are its ease of manufacture; its ease of application; it may be tightened without damaging its own or its mating threads; it may be removed from a bolt without excessive dif ficulty; and it may be used again and again on the same bolt or on a diierent bolt. In addition, the lockenut locks itself to a bolt by a clamping action strong enough to resist loosening under severe vibration or repeated heavy shocks.

The application just described may be operated as follows:

Crank i I3 is turned clockwise or counter-clockwise, as required, to adjust the width of space i553 between squeeze rolls 37 and 33 to accommodate the particular size of nut blank |41 to be deformed. In Fig. 17, for example, the nut is relatively small while in Fig. 9 it is relatively large. Operation of crank ||3 simultaneously adjusts the space between parallel guide wires FiI' and |92. Motor 4l is started which in turn sets squeeze rolls 3l and 38, endless conveyor 36 and knurling device 39 in motion. The driving parts are so proportioned and correlated that the end less conveyor, squeeze rolls and knurler move at substantially the same linear speed. A nut blank- |47 is mounted on the free end of each mandrel Mt as it 4apprcaclfies the parallel guide wires and the squeeze rolls. If a corner or corner portion of the nut strikes guide wire |32, the nut is turned on the mandrel to align a pair of its opposite sides in parallel relationship with the guide wires. This relationship is maintained as the nut moves forward into additional sliding contact with guide wire |9|. This operation assures proper presentation of the nut to the squeeze rolls.

The squeeze rolls and the nut on the mandrel are so positioned that only the upper portion of the nut comes into squeezing engagement vwith the rolls, the depth of squeeze, `as pointed" out above, being 1A; to 1/2 the nominaldiameter of @infima ='-resiiltant force extends downwardlyttowar'dliat- '-erallyext`ending base iddof the'-ma1idrel.

Crankfi i3 is suitably turnedftoiproviderspace "'f-Blbetween the squeeze rolls with; i-al'ieKnecessary #width to` deform the upperv'portionrof thenutthe M forces' -being directed inwardly toward the? fh'ole ."drell-v actingasa stop against excessive#` deforma tion-*while at Athe same time assuring `eachf-suc- JIJceeding nut-of anequivaent-amountof'dformaionffalling within "the 'lirnitsfabovetmeiitioned;fJ

1In-fpractice,- nuts `as vthey comef'f'fro'rnffthe7 squeeze trolls measured to determine.i-whthert'fthe width of the top of the opening along theeminor ffaxis is reduced by the distortiowbyi aneamount They are preferably tested'withf a-torqueffwrench tofdetermine yWhether"'thefwidth of the top of the opening along the minor axis is reduced by the distortionby'an:amount'toproduce a friction locking torque of 115 132-4 to 820 D2-5 on a mating@ screw within the dimension tolerance of its class of fit; in which, as previously pointed out, D

equals the nominal diameter of the mating screw f and the result obtained is pound inches of torque. An intermediate optimum value is selected and crank H3 is turned this way or that until the distorted nuts coming from the squeeze rolls match that value. Such checks and adjustments, if necessary, are made from time to time during the course of a days operation of the apparatus to make certain that the lock nuts produced are substantially uniform in their friction locking torque.

Although provision is made for knurling the top of each lock nut as it leaves the squeeze rolls, this is a convenience rather than a necessity. Furthermore, the nut blank could be knurled before it enters the squeeze rolls, or for that matter, before it is mounted on its mandrel. Among important advantages of the practice disclosed are the following: The knurled top at once identiiies the nut as a lock nut. i Second, it indicates to the user that the knurling is adjacent the upper or distorted portion of the nut and that the un-knurled bottom should be presented to a mating bolt to assure easy screwing of the nut at least until the first threads of the bolt come into interfering or locking engagement with the distorted threads of the lock nut. In addition, a distinctive knurling design may be employed to identify the manufacturers particular brand of lock nut.

In any event, as a given mandrel and nut are carried as a unit by the conveyor between the squeeze rolls, they pass under and in contact with knurling roll 265. As pointed out above in sui-licient detail, various parts of the knurling device may be manipulated to vary the pressure of the roll on the top of the nut to assure the desired marking.

The conveyor then carries each succeeding knurled lock nut while still mounted on its mandrel to strippers 312 and 3|3 where the nuts are forcibly removed, dropped first into chute 315 and then into bin 3|6.

It will be vclear to those skilled in this art that the specic method and apparatus just described may be suitably varied while still falling within the purview of the invention.

This application is a division of my co-pending in they nut and being of sufcient magnitudezto permanently distort the nut and causehthefhole v|-`*at said'y endto assume a generally elliptical shape, @and positively` opposing each of ls'aidf"distorting if'forces, independently ofthe othery-lwith.-anf'equal anduoutward forceafter a predetermineddnward movement of said opposite vsides of vthewnut, lthereby limiting the'l amount "ofr said-distortion. The'metho'd as denedin claim l, in which Ll.go-vsaid-outward forces are Ydirectedagainstithe, iit.

l '13. The f method as defined infclaim.y l, c inizwv l ich said outward forces are directed against theiw'all .--f-'ofthe'vhole in' theLnut.

45; The'rnethod :as `defined-'in claim l; :in which :saidoutward forces are directed.fagainststheinut before said distorting forces candistor-t-the I.other end of the nut, whereby one end of the hole remains substantially circular.

5. The method as deiined in claim 1, in which said distorting forces and said outward forces said outward forces are applied to the nut only after the distorting forces have reduced the width of the hole at said first end of the nut, valong the minor axis, by an amount equal to the t tolerance plus 0.001 to 0.010 inch.

7. The method as dened in claim l, in which said outward forces are applied to the nut only after the distorting forces have reduced the width of the hole at said first end of the nut, along the minor axis, by an amount suflicient to produce a friction locking torque of D2-4 to 820D@5 on a mating screw within the dimensional tolerance of its class of fit; in which D equals the nominal diameter of the mating screw and the result obtained is pound inches of torque.

8. The method as defined in claim 1, in which said distorting forces and said outward forces are applied to said first end portion of the nut to a depth of 1/4 to 1/2 the nominal diameter of the mating screw for the nut, and in which said outward forces are applied to the nut only after the distorting forces have reduced the width of the hole at said rst end of the nut, along the minor axis7 by an amount equal to the t tolerance plus 0.001 to 0.010 inch.

9. The method as defined in claim 1, in which said distorting forces and said outward forces are applied to said rst end portion of the nut to a depth of 1A; to 1/2 the nominal diameter of the mating screw for the nut, and in which said outward forces are applied to the nut only after the distorting forces have reduced the width of the hole at said first end of the nut, along the minor axis, by an amount sufcient to produce a friction locking torque of 115D2-4 to 820D2-5 on a mating screw within the dimensional tolerance of its class of fit; in which D equals the nominal diameter of the mating screw and the result obtained is pound inches of torque.

10. In the manufacture of lock nuts from nuts, in a continuous operation, the method which 15 comprises supporting the nuts in spaced relation to a locus of compression, effecting relative movement between the nuts and said locus to cause the nuts to move consecutively through the locus, subjecting each nut in said locus to opposing forces against substantially opposite sides of the nut at one end portion thereof, said forces being directed inwardly toward the hole in the nut and being of suilcient magnitude to permanently 'distort the nut and cause the hole at said end a predetermined inward movement of said op posite sides of the nut, thereby limiting the amount of said distortion.

11. The method as dened in claim 10, in which said distorting forces and said outward forces are applied consecutively to the nuts during the relative movement between the nuts and said 12. The method as dened in claim 10, in which said outward forces are applied to each nut at the wall of the hole in the nut during said relative movement.

13. In the manufacture of a. lock nut from a nut, the method which comprises supporting the nut in spaced relation to a locus of compression, effecting relative movement between the nut and said locus to cause the nut to move through the locus, progressively compressing one end portion of the nut with a rolling action at substantially opposite sides during its movement through the locus, to permanently distort the nut and cause the hole at said end to assume a generally elliptical shape, and, during said relative movement, positively opposing the compressional force at each side of the nut, independently of the compressional force at the opposite side, with an equal and outward force after a predetermined inward movement of said opposite sides of the nut, thereby limiting the amount of said distortion.

14. The method as dened in claim 13, in which said outward forces are applied to the nut at the inner wall of said hole.

JORDAN H. STOVER, III.

No references cited. 

